Brachytherapy is the treatment of cancer by the insertion of radioactive implants directly into the tissue near the tumor. The implants are minute radioactive pellets known as seeds. The seeds and, optionally, non-radioactive pellets known as spacers, are lined up end-to-end in strands that are held together in a sleeve until implant. The pellets are held in the sleeve, which is placed in a needle and secured there by plugging the end with bone wax. The loaded sleeve is then inserted into the patient's tissue at the desired location.
Seeds of a given radioactive species and dosage are provided in a magazine, which in turn is held in a shielded case to protect humans from excess radiation exposure before and during the implant procedure. The seeds are extracted from the magazine and inserted into the sleeve. A variety of seed loaders exist for this purpose. The sleeve is inserted into a patient using a needle.
The amount of radiation to be delivered to the patient and placement pattern of the sleeves are determined in advance of the treatment. The sleeves are prepared accordingly, either pre-loaded per the irradiation plan before treatment or as the insertions are carried out during treatment. Once the treatment starts, the physician may determine that a different dosage or placement is needed, and the seeds and spacers need to be rearranged.
Loading a sleeve is a delicate process, and re-arranging the seeds and spacers as they go into a sleeve is very difficult. It would be desirable to have a loader that makes it easy to load seeds and spacers, and to easily rearrange them prior to inserting them into the sleeve.